In general, an automotive air conditioning device comprises an intake unit for introducing outside and inside air, a cooler unit for cooling the introduced air and a heater unit for heating the introduced air, these three units being combined in series and installed in a limited space of a vehicle cabin, such as a space defined below an instrument panel.
However, due to the in-line connection of the three units, the automotive air conditioning device is compelled to have an enlarged size. Thus, when such device is mounted in a small car, the smaller vehicle cabin space is further limited, which is undesirable.
In view of the above, as is shown in FIG. 16, there has been proposed a device in which a cooler unit 101 and a heater unit 102 are positioned close to each other and aligned along a fore-and-aft direction of the vehicle thereby to reduce not only a longitudinal size "L" of the vehicle but also a lateral size of the same. Furthermore, in this device, for reduction of size, the distance between an evaporator 103 and a heater core 104 is reduced and a mix door (which will be referred to as just "door" hereinafter) 105 for producing cooler and/or warmer air is reduced in size.
As is known, the evaporator 103 is a device through which a low temperature low pressure refrigerant, which flows in a refrigerating cycle, flows for producing a cooled air by conducting a heat exchange between the refrigerant and an induced air. While, the heater core 104 is a device through which a highly heated engine cooling water flows for producing a heated air by conducting a heat exchange between the cooling water and an induced air.
Denoted by numeral 106 in the drawing is a defroster door which, in a defrosting mode, opens a defroster opening 106a for defrosting a window, denoted by numeral 107 is a ventilation door which, in a ventilation mode, opens a ventilation opening 107a for blowing a cooled air against an upper part of a passenger, and denoted by numeral 108 is a foot door which, in a foot mode, opens a foot opening 108a for blowing a warmed air toward the lower part of the passenger.
However, in the unit having the above-mentioned construction, the reduction in size of the door 105 tends to cause a difficulty with which distribution of cooled air and warmed air is controlled. Thus, in some devices, as is illustrated by a broken line in the drawing, an auxiliary door 105a is provided for controlling the amount of air led to the heater core 104. However, in this case, the addition of such auxiliary door causes a complicated and highly expensive construction, which is of course undesirable.
Accordingly, recently, there has been proposed, as is shown in FIG. 17, a much compact automotive air conditioning device (see Japanese Utility Model Provisional Publication 6-71222).
In the device, for achieving the compact construction, a cooler unit 101 and a heater unit 102 are integrated, and an evaporator 103 and a heater core 104 are positioned close to each other. That is, since, like in case of the mix door 105 arranged between the evaporator 103 and the heater core 104 and supported at one fulcrum as shown in FIG. 17, turning the door 106 about the fulcrum needs a relatively larger mounting, a flat plate door 109 (the door shown in the drawing comprises two doors 109a and 109b which are connected through pins "pa" and "pb" to a door actuating mechanism comprised of a link mechanism) is employed, the flat plate door being slid up-and-down along a rail 109c for effecting the temperature control.
However, a door mechanism possessed by the above-mentioned vertically sliding type tends to have a higher resistance against air passage and thus tends to show weak points in operability. That is, since the above-mentioned door 109 disclosed by the publication is of a flat and straight type, the air flow is forced to collide against the door at right angles, which brings about a higher air flow resistance causing reduction in air flow. When this air flow reduction occurs under a cooling condition of the air conditioner, the passengers can not get a satisfactorily cooled air.
In order to prevent air leakage around the door 109, it is necessary to remove or minimize a clearance provided between the rail 109c and the door 109. However, if the clearance is too small, the sliding resistance of the door becomes increased causing a non-smoothed movement of the door 109. This undesired phenomenon equally occurs even when a sealing member is arranged between the door 109 and the rail 109c. While, if, for achieving a smoothed movement of the door, a larger clearance is provided between them, the undesired air leakage tends to occur. That is, in this case, antinomic matters take place.
Furthermore, in a case wherein, like the door 9 of the above-mentioned publication, the sliding mechanism is composed of a link mechanism, the connection between the pin and the link tends to produce a play upon operation of the door. When the door is applied with a certain wind pressure, noises caused by the play tend to be produced, which are transmitted to the vehicle cabin to make passengers uncomfortable.
The present invention is provided for eliminating the above-mentioned drawbacks possessed by the conventional techniques. That is, a first object of the invention is to provide an excellent door mechanism of an automotive air conditioning device, which assures a compact construction of the unit, reduction in air flow resistance, smoothed operation, satisfied sealing and satisfied air temperature controlling without producing noises.
Furthermore, as is seen from FIG. 16, in general, in a heater unit, around a mixing chamber 111, there are arranged a defroster opening 106a, a ventilation opening 107a and foot opening 108a. To these openings, there are connected mode doors, such as a defroster door 106 and a ventilation door 107. When one of the mode doors is actuated, the same is projected into the mixing chamber 111. If the mode doors are designed to pivot in a direction away from the mixing chamber 111, the size of the entire construction of unit becomes increased, which is not preferable.
Each time one of the mode doors is actuated, the direction of air flowing in the mixing chamber 111 is forced to change and thus desired and stable mixing between cooled air and warmed air is not obtained. Furthermore, the presence of the mode doors causes a marked increase in air flow resistance and production of noises.
For example, in a ventilation mode, by the function of the mix door 105, part of the cooled air from the evaporator 103 is led into a bypass passage "B" and remaining part of the cooled air is led toward the heater core 104 to be warmed. The cooled air and warmed air are mixed in the mixing chamber 111 for blowing from the ventilation opening 107a an air having a predetermined temperature.
However, when the defroster door 106 takes a position to open the defroster opening 106a, the defroster door 106 is projected into the mixing chamber 111 and thus the flow of the cooled air in the bypass passage "B" is disturbed by the projected defroster door 106, which changes the air distribution region in the mixing chamber 111. Thus, stable mixing between the cooled air and warmed air is not achieved and thus stable air temperature controlling becomes difficult. In view of this drawback, some conventional devices are equipped with a fixed temperature controlling rib in the mixing chamber 111 for obtaining a stable air temperature controlling.
However, in case wherein the air temperature controlling rib is employed, it is difficult to determine the size of the temperature controlling rib and the positioning of the same. Furthermore, due to employment of the temperature controlling rib, the number of parts increases and thus assembling work of the case becomes difficult or at least troublesome, and cost is increased. Furthermore, due to presence of the temperature controlling rib in the mixing chamber 111, the chamber has a non-negligible air flow resistance, which tends to induce that a satisfied amount of air is not fed to the vehicle cabin. Furthermore, even when the air temperature controlling rib is so positioned and sized as to exhibit the best ventilation mode, it often occurs that the air temperature controlling rib has a bad effect on the temperature controlling in the other mode (viz., the mode other than the ventilation mode, wherein the ventilation door 107 is closed and another door is opened).
Although the above-mentioned example is an example applied to the defrosting mode, similar drawbacks tend to appear in case of the ventilation mode and/or the foot mode.
The present invention is provided for eliminating the above-mentioned drawbacks possessed by the conventional techniques. That is, a second object of the present invention is to provide a door mechanism of an automotive air conditioning device, which can exhibit a stable mixing of cooled air and warmed air irrespective of the mode selected, a reduction in air flow resistance, an excellent air temperature controlling and a compact, simple and economical construction.
A further object of the present invention is to provide a unit which is very compact in size due to unemployment of the foot duct.
Apart from the above, an air conditioning device is widely known wherein as a ventilation opening, there is provided, in an upper wall of a case positioned above the mixing chamber, a center ventilation opening, and near right and left side portions of the center ventilation opening, there are provided side ventilation openings, so that in a ventilation mode, the air whose temperature has been suitably adjusted in the mixing chamber is blown out from the center ventilation opening and the side ventilation openings.
However, in the above-mentioned air conditioning device, the side ventilation openings are formed in the right and left side portions of the center ventilation opening, that is, in a limited space positioned above the upper wall of the case. Thus, the center ventilation opening and the side ventilation openings are each obliged to have a reduced area and thus the air flow resistance of them increases thereby reducing the amount of air blown into the vehicle cabin from such openings.
Depending on the type of the associated vehicle, there is an arrangement wherein when the center ventilation opening is fully closed, part of the temperature-controlled air is blown from the side ventilation openings toward door side window panels to defrost the same. Since, in this arrangement, the ventilation door for opening and closing the center ventilation opening is used for controlling the air distribution, tuning of the air flow amount is difficult.
Accordingly, a third object of the present invention is to provide an automotive air conditioning device, which needs not to reduce the open area of the center ventilation opening and that of the side ventilation opening, can increase the amount of temperature-controlled air blown from these openings and can easily control the amount of air in case wherein a mode is so set that the air is constantly leaked from the side ventilation openings.